Characoidei

African tetras (family Alestidae, formerly spelled Alestiidae) are a group of characiform fish found exclusively in Africa. This family contains about 18 genera and 119 species. Among the best known members are the Congo tetra and African tigerfish; both are kept in aquaria, and tigerfish are utilized for food and as gamefish.

The freshwater hatchetfish are a family, Gasteropelecidae, of ray-finned fish from South and Central America. The common hatchetfish is the most popular member among fish keeping hobbyists. The family includes three genera: Carnegiella (four species), Gasteropelecus (three species), and Thoracocharax (two species).

The Lebiasinidae are a family of freshwater fishes found in Costa Rica, Panama, and South America. They are usually small and are known as ornamental fishes in aquaria, including popular fishes such as the various pencilfish and the splashing tetra.

The Serrasalmidae (serrasalmids) are a family of characiform fishes native to freshwater habitats of South America. They include more than 90 species. The name means "serrated salmon family", which refers to the serrated keel running along the belly of these fish. Fish classified as Serrasalmidae are also known by these common names: pacu, piranha, and silver dollar. These common names generally designate differing dental characteristics and feeding habits.

Cynodontidae, from Ancient Greek κύων (kúōn), meaning "dog", and ὀδούς (odoús), meaning "tooth", also known as dogtooth characins or vampire tetras, are a family of predatory, characiform freshwater fishes from South America. This group is not very diverse, and includes only three genera and eight species. The largest species in this family ranges up to .

The Curimatidae, toothless characins, are a family of freshwater fishes, of the order Characiformes. They originate from southern Costa Rica to northern Argentina. The family has around 105 species, many of them frequently exploited for human consumption. They are closely related to the Prochilodontidae.

The Erythrinidae are a family of fishes found in rivers and other freshwater habitats from Costa Rica south as far as Argentina. They are common and are caught with hooks by fishermen, partially because of their voracious behaviour. They are sometimes called trahiras (also spelled trairas) or tarariras.

The Anostomidae are a family of ray-finned fishes that belong to the order Characiformes. Closely related to the Chilodidae and formerly included with them, the Anostomidae contain about 150 described species. Commonly known as anostomids, they are found in freshwater habitats from the Río Atrato in northernmost South America to warm-temperate central Argentina; they are of Amazon origin, with few found west of the Andes (mainly in Colombia and Venezuela). Their scientific name approximately means "mouth on top", from Ancient Greek áno- (ἄνω) "up" (as an adverb) + stóma (στόμᾶ) "mouth", in ref

Ctenoluciidae the pike-characins, is a small family of freshwater ray-finned fishes belonging to the order Characiformes, the characin-like fishes. The fishes in this genus are found in Panama and South America.

The Prochilodontidae, commonly known as the bocachicos or flannel-mouthed characins, are a small family of freshwater fishes found primarily in the northern half of South America, south to Paraguay and northern Argentina. This family is closely related to the Curimatidae, and were included in Characidae before that family was revised and split.

The Chilodidae, or headstanders, are a small family of freshwater characiform fishes found in northern and central South America. This family is closely related to the family Anostomidae and is sometimes treated as a subfamily, Chilodinae, within Anostomidae.

The Parodontidae, the scrapetooths, are a family of fresh water ray-finned fish belonging to the order Characiformes. The fish in this family are rheophilic and are specialised for feeding by scraping algae off rocks. The fish in this family are found in the tropical and subtropical Neotropics.

The Hemiodontidae are a small family of freshwater characins found in northern South America, south to the Paraná-Paraguay Basin. The larger species are popular food fish.

The Crenuchidae, or crenuchids, are a family of freshwater fish of the order Characiformes. The 11 genera include about 115 species, though several species are undescribed. These fish are relatively small (usually under in standard length) and originate from eastern Panama and South America. Both subfamilies were previously included in the family Characidae, and were placed in a separate family by Buckup, 1998. Buckup, 1993, revised all genera, except Characidium.

Chalceus is a genus of fish that inhabits freshwater habitats in South America. Members can be found in the Amazon and Orinoco basins, as well as in the Guianas and various tributaries of the former. It is the sole representative of the family Chalceidae, the tucanfishes.

Acestrorhynchidae is a family of freshwater fish in the order Characiformes, found in South America. Members of this family are known as freshwater barracudas (not to be confused with the unrelated true barracudas of the Sphyraenidae) and biting tetras.

Hepsetus is a genus of freshwater ray-finned fishes belonging to the monotypic family Hepsetidae, the African pikes or African pike characins, in the order Characiformes. It was long believed that only a single widespread species existed, H. odoe, but studies in 2011–2013 have shown that this species is restricted to parts of West and Central Africa. The well-known species of southern Africa, including Kafue River, is Hepsetus cuvieri. These predatory fish reach up to in length.

Bryconidae, also known as bryconids, is a family of freshwater fishes belonging to the order Characiformes. They are native to South America. Some species reach particularly large sizes for characins, with Salminus franciscanus being one of the largest characiforms overall.

species of fish

Iguanodectidae is a family of freshwater fish in the order Characiformes that lives in South America. It contains three genera: Iguanodectes, Piabucus, and Bryconops. Several species in the family, such as the green line lizard tetra (Iguanodectes spilurus), the tailspot tetra (Bryconops caudomaculatus), and the orangefin tetra (Bryconops affinis), are sometimes taken as aquarium fish.

Triportheidae, the hatchet characins, is a family of characiform fishes, including about 23 species. This family was raised from the status of a subfamily to family based on extensive analysis of characiform species.

Tarumania is a genus of freshwater fish described in 2017. It contains a single species, Tarumania walkerae, and constitutes the only genus in the family Tarumaniidae. T. walkerae is a predatory species that hunts among the leaf litter on the bottom of flooded forests in the Rio Negro drainage basin.